Your phone or laptop is taking far longer to charge than it used to, and every answer online is a list of things to replace. Some of it is deliberate.
Charging is slowed on purpose in more situations than people realise, and on a laptop you can read the actual rate rather than guessing at it.
I read what this machine reported while plugged in, and the number surprised me.
Ours: plugged in, and charging at zero
The measurement, and the first lesson is in it.
Ours, and this is what the PC here reported. Battery at 100%, power online, charging false, and a charge rate of 0 milliwatts.
⭐ All four of those together are completely normal. A full battery on mains stops charging and runs off the wall.
⛔ That exact state is what people describe as plugged in and not charging. Nothing is wrong with it.
⚡ Read your own rate. It only looks:
Get-CimInstance -Namespace root\wmi -ClassName BatteryStatus | Select-Object PowerOnline, Charging, ChargeRate⚠️ A rate in milliwatts is the real number. Compare it with the wattage printed on your charger and you know whether you are getting what you paid for.
The deliberate slowdown on phones
Apple's own words, and it is the commonest answer.
Documented by Apple on its charging page: "When the feature is enabled, your iPhone will delay charging past 80 percent in certain situations."
Why: it "is designed to reduce the wear on your battery and improve its lifespan by reducing the time your iPhone spends fully charged."
⭐ It is not random. Apple explains that the phone "uses on-device machine learning to learn your daily charging routine".
⚡ Apple also gives the conditions: it "needs at least 14 days to learn your charging habits", and "at least 9 charges of 5 hours or more in a given location".
⚠️ And there is a separate hard limit you may have set. Apple describes choosing "a charge limit between 80 percent and 100 percent in 5 percent increments", after which the phone stops.
⛔ So a phone that parks at 80 overnight is working correctly. That is the feature, not a fault.
⚠️ We could not find anything on that page about charging being slower below 80 percent, or about laptops at all. Apple describes a delay rather than a slower rate.
The four that genuinely slow a charge
The real causes, in the order worth checking.
⛔ The charger's wattage. A phone charger will charge your laptop, extremely slowly, and everything looks normal while it does.
⭐ The cable. Charging cables are rated too, and a thin one caps the current no matter what the charger can supply.
⚡ The port. A USB port on a laptop or a monitor supplies a fraction of what a wall socket does.
⚠️ And heat. Every device slows its own charging when the battery is warm, deliberately, and a phone under a pillow will crawl.
Using it while charging
Simple arithmetic that catches people out.
⭐ A device drawing power while charging charges slower. Gaming or video calls can outpace a small charger entirely.
⚡ On a laptop, that shows up as a charge rate near zero while plugged in and in use. The reading above will show it.
⚠️ A machine that is also working hard is worth a second look. Something running flat out shows in Task Manager and it heats the battery too.
When it is the battery itself
The end of the list, and the least welcome part of it.
⛔ An old battery charges slower and holds less. That is chemistry, and no setting on your device reverses it.
⚠️ A laptop that will not charge at all rather than slowly is a different fault. The number it stopped at is the clue there.
⭐ And a phone whose battery drains as fast as it charges has a different problem again. Drain has its own list and it is usually software.
What this page cannot tell you
Stated plainly, in its own section.
⛔ No phone was tested here. The Apple behaviour is quoted from Apple, and the only reading I took was on the Windows laptop this was written on.
⭐ What is solid: I ran the charge rate command here and it works on any Windows laptop. Apple's wording on the 80 percent delay is quoted rather than described.
Status: read against Apple's charging documentation, 25 August 2026, and measured on Windows 11. Apple supplies the delay past 80 percent, the reason for it, the machine learning explanation, the 14 day and 9 charge conditions and the Charge Limit range. The battery percentage, power state, charging state and charge rate were read on the PC here. ⛔ No phone was measured.
Why does my phone stop charging at 80 percent?
Because Apple delays charging past 80 percent on purpose, to reduce wear and extend battery life. It learns your routine first, needing at least 14 days and at least 9 charges of 5 hours or more in one place. It is the feature working, not a fault.
Why does my laptop say plugged in but not charging?
At 100 percent that is normal. The battery is full, so the machine runs from the wall and the charge rate reads zero. Check the percentage before assuming anything is wrong.
How do I find out how fast my laptop is actually charging?
Read the charge rate in milliwatts with the one line above. Compare it with the wattage printed on your charger. That turns a guess into a number, and it is the fastest way to catch an underpowered charger.
Does using a device while charging slow it down?
Yes, and sometimes to a standstill. If the machine draws more than the charger supplies, the battery does not gain anything. On a laptop the charge rate reading will sit near zero while it happens.
Does a thin cable really matter?
Yes. Cables are rated for current, and a thin one caps what reaches the device no matter how good the charger is. It is the cheapest thing on the list to rule out.
The Short Version
- The PC here read 100 percent, online, not charging, at zero milliwatts. All normal.
- That exact state is what people call plugged in and not charging.
- Apple delays charging past 80 percent deliberately, to reduce battery wear.
- It needs 14 days and at least 9 long charges in one place before it engages.
- Charge Limit is separate again, and stops the phone at a figure you pick.
- Charger wattage, cable rating, port type and heat are the four real causes.
- Using a device while it charges can cancel the charge out entirely.
- Read the rate in milliwatts and compare it with what is printed on the charger.
Where to Next
Read your laptop's actual charge rate with the line above, then look at the wattage on the charger. Two numbers, and the gap between them is your answer.
On a phone, check whether it is parking at 80 percent. If it is, that is the battery feature doing its job.
If the charge itself is fine but it empties too fast, you are looking at the wrong number. Battery health is a separate reading and Windows never shows it.
Swap the cable before buying anything. It is the cheapest cause on the list and the most common.
Anyone who found a charger delivering far less than its label, say which one in the comments. Those are worth naming.
Isaac Smith is the founder and editor of PC Glance, a website that covers computers, laptops, and technology. He is a tech enthusiast and a computer geek who loves to share his insights and help his readers make smart choices when buying tech gadgets or laptops. He is always curious and updated about the latest tech trends.